Such a small benchmark:

[
| a |
a := Array new: 1.
10000000 timesRepeat: [ a at: 1 put: 3.]
] millisecondsToRun

Strongtalk (best time from 10 runs): 
 ... 45 ms ... 100 %
VisualWorksR NonCommercial, Release 5i.3 of January 30, 2001 
 ... 220 ms ... 488 %
Dolphin Smalltalk Pro 4.0.1. 
 ... 820 ms ... 1822 %
Squeak3.2-4956 
 ... 2410 ms ... 5355%
Kathmandu Objects (my poor Smalltalk) 
 ... 7881 ms ... 17513 %
Visual C++ (see code bellow) 
 ... 14 ms ... 31 %

DWORD BegTime = ::GetTickCount();
DWORD *Array = new DWORD [1];
for (DWORD Index = 0; Index < 10000000; Index++)
 {
 Array [0] = 3;
 };
DWORD TotalTime = ::GetTickCount() - BegTime;
delete Array;

AMD TB1,4 GHz